Electrical apparatus comprising a voltage commutator



y 5 1963 J. VAN DEN DRIEST 3,098,133

ELECTRICAL APPARATUS COMPRISING A VOLTAGE COMMUTATOR Filed June 3, 1960 INVENTOR JAN VAN DER DRIEST.

AGENT United States Patent 3,098,133 ELECTRICAL APPARATUS COMIRISING A VOLTAGE COMMUTATQR Jan van den Driest, Drachten, Netherlands, assignor to North American Philips (Iompany, Inc, New York, N.Y., a corporation of Delaware Filed June 3, 1960, Ser. No. 33,782 Claims priority, application Germany June 4, 1959 2 Claims. (Cl. 2tlil51.07)

The invention relates to an electrical apparatus comprising a rotatable and arrestable voltage commutator, having plug pins and separate cormnutating contacts. In a known device of this kind the locking of the commutator is obtained by means of a spring. This device has the disadvantage that during the operation of the tapparatus the commutator may readily turn unpe-rceived and go over to a lower main voltage, which may destroy the apparatus.

The invention has for its object to obviate this disadvantage by a simple measure. In accordance with the invention this is achieved in that a non-circular part of the female plug associated with the apparatus subsequent to its complete insertion, cooperates with an elevated part on the housing of the apparatus in a manner such that a turn of the female plug and of the commutator with respect to the apparatus is no longer possible.

The invention will be described more fully with reference to the accompanying drawing, in which:

FIG. 1 is a perspective view of part of the apparatus according to the invention in a dismounted state,

FIGS. 2, 3 and 4 are elevations of various component parts of the device shown in FIG. 1,

FIG. 5 is a perspective view of a female plug associated with the apparatus illustrated in FIG. 1, and

FIG. 6 illustrates the operation of this plug.

FIG. 1 shows part of the housing 1 and of the associated cover 3 of an electrical shaving apparatus, provided with a rotatable voltage commutator 5. The voltage commutator 5 comprises a commut-ating member shaped in the form of a disc 7 of insulating material, for example, plastic, which is rotatably arranged in .an insulating, square frame 9. The disc 7 is provided on one side-in FIG. 1 the front sidewith two plug pins 11, secured at right angles to the disc and connected with two switching contacts 13, provided on the rear side of the disc (see FIG. 2, which shows the rear side of the disc 7). The movable contacts 13 are capable of cooperating with each pair of a group of four counter-contacts, formed by the end 15 of four soldering tags 17, bent over at right angles and inserted into fitting slots 19 of a square plate 21 of insulating material (see FIGS. 3 and 4, which show the front side and the rear side respectively of the plate 21). The plate 21, :as is evident from FIG. 4, is secured by means of a U-shaped, resilient strap 23, on the rear side in the frame 9 and locks the eommutating member 7 in this frame. The slightly resilient ends 15 of the soldering tags 17 may be provided with embossed elevations 25, which can fall into small depressions 27 of the commutating contacts 13, so that the commutating member 7 is arrested in the desired positions. The arrangement of the apparatus, which is not shown entirely for the sake of clarity, may be such that, in the position shown, of the commutating member 7, the apparatus is suitable for a mains voltage of 220 v., whereas in a position turned through 180 of the disc 7, the apparatus can be connected to a mains voltage of 110 v. The adjustment can be read in the manner shown in FIG. 1, since the two voltages are indicated at two diametrically opposite spots on the front side of the disc 3,098,133 Patented July 16, 1963 ice 7, whilst one of the two indications is covered by a plate 29, which forms part of the frame 9.

In the operational state the commutator 5 is located in a fitting groove 31, which is provided in the housing 1 and in which the commutator is locked by the cover 3, screwed onto the housing 1.

FIG. 5 shows a female plug 33, by means of which a connecting lead 35 can be connected to the apparatus shown in FIG. 1. The insulating body of the plug 33 has a non-circular, in this case rectangular portion 37, which is adapted to co-operate with an elevation of the housing 1 of the shaving apparatus so that, after the female plug has been completely inserted into the apparatus, a rotation of the plug relative to the housing of the apparatus is no longer possible. In the present case the cross-section of the portion 37 of the plug 3-3 at right angles to the direction of insertion is rectangular, whilst the housing of the apparatus comprises, as is shown in FIG. 1, an internally rectangular elevation 39, fitting around the portion 37 of the plug and being completed by the front part of the cover 3. The plug 33 may be provided, at the free end--the end entering first the housing 1 upon insertion-with a terminal part 41, which may be circular, is rotatable within the elevation 39 and is provided with bores 43, fitting to the plug pins 11. These bores are in line with the contact bushes 45 of the female plug 33, which means that the contact bushes 45 do not extend as far as into the round part 41 of the plug. FIG. 6 illustrates the manner in which, by inserting the plug up to the non circular part 37 into elevation 39 of the housing 1 a mechanical contact between the plug on the one hand and the pins 11 and the switching member 7 on the other hand can be established whilst an electrical connection is not yet being established. By turning the plug 33 the commutator can thus be adjusted in unloaded condition to the position of the desired mains voltage. After the adjustment the complete insertion of the plug 33 into the elevation 39 of the housing 1 will establish the electric connection between the contacts 45 and 11, whilst at the same time, owing to the co-operation of the elevation 39 with the non-circular part 37 of the plug 33, the latter is locked against further rotation.

If the part 41 of the counterplug 33 is lacking, the rotation .of the commutat-ing member 7 is to be carried out by turning the pins 11 with the finger.

What is claimed is:

1. An electrical connector for electrical apparatus comprising a housing member for said apparatus having an elevation portion defining an aperture, a transverse locking groove within said elevation portion adjacent one end of said aperture adapted to receive commutator means having pins located within the aperture of said elevation portion, counterplug means receivable within said elevation portion, said counterplug means comprising an intermediate portion fitting within the said aperture for preventing relative rotation therebetween and having contact means adapted to engage said pins, a terminal portion projecting from one side of said intermediate portion having means adapted to engage said pins for rotation of said commutator with said aperture without electrically connecting said pins and counterplug, and a plug portion on the other side of said intermediate portion.

2. Electrical apparatus comprising a housing member having an apertured wall portion, rotatable commutator means secured in said wall portion adjacent one end of the aperture thereof, counterplug means having a terminal portion freely rotatable Within said aperture, means associated with said terminal portion to non-electrically engage said commutator means for rotation through a predetermined angle and means associated with said counter-plug means adjacent said terminal portion to electrically connect said :counterplug means with said commutator means and adapted to removably secure said counterplug means against rotation "relative to the housing member.

References Cited in the file of this patent UNITED STATES PATENTS Winter Aug. 9, 1932 Robinson Mar. 16, 1954 Simpson Oct. 21, 1958 

1. AN ELECTRICAL CONNECTOR FOR ELECTRICAL APPARATUS COMPRISING A HOUSING MEMBER FOR SAID APPARATUS HAVING AN ELEVATION PORTION DEFINING AN APERTURE, A TRANSVERSE LOCKING GROOVE WITHIN SAID ELEVATION PORTION ADJACENT ONE END OF SAID APERTURE ADAPTED TO RECEIVE COMMUTATOR MEANS HAVING PINS LOCATED WITHIN THE APERTURE OF SAID ELEVATION PORTION, COUNTERPLUG MEANS RECEIVABLE WITHIN SAID ELEVATION PORTION, SAID COUNTERPLUG MEANS COMPRISING AN INTERMEDIATE PORTION FITTING WITHIN THE SAID APER- 